This invention relates to the production of aluminum phosphate. The production of aluminum phosphate by combining aqueous solutions of an aluminum salt and a source of phosphate ions, such as phosphoric acid, followed by neutralization with a base to give a precipitate or a true hydrogel is well known in the art. The resulting phosphate has been disclosed to have several utilities including use as a support for chromium oxide catalysts. There is considerable progression in the art with regard to the preparation of aluminum phosphate catalysts with the newer art suggesting forming the gel at a relatively high pH in order to obtain a higher surface area product. Generally, the art suggests converting the hydrogel to a xerogel by means of simple oven or tray drying or spray drying although it is incidentally taught in the art to wash with a water miscible liquid, such as an alcohol.
At least as it relates to a base for chromium catalysts, even the most advanced teachings of the prior art still do not produce a base which has found favor as a chromium catalyst support for olefin polymerization. Thus, chromium catalysts are generally supported on silica-containing bases similar to those used decades ago when the chromium catalyzed polymerization of olefin polymers first became commercial.